A wounded Syrian boy receives treatment at a make-shift hospital following reported government shelling on the rebel-held town of Douma, east of the Syrian capital Damascus, on October 26, 2016. (Photo by Abd Doumany/AFP Photo)

People inspect a damaged site after an air strike Sunday in the rebel-held besieged al-Qaterji neighbourhood of Aleppo, Syria October 17, 2016. (Photo by Abdalrhman Ismail/Reuters)

People walk near a damaged vehicle after an air strike Sunday in the rebel-held besieged al-Qaterji neighbourhood of Aleppo, Syria October 17, 2016. (Photo by Abdalrhman Ismail/Reuters)

People remove belongings from a damaged site after an air strike Sunday in the rebel-held besieged al-Qaterji neighbourhood of Aleppo, Syria October 17, 2016. (Photo by Abdalrhman Ismail/Reuters)

People remove belongings from a damaged site after an air strike Sunday in the rebel-held besieged al-Qaterji neighbourhood of Aleppo, Syria October 17, 2016. (Photo by Abdalrhman Ismail/Reuters)

Internally displaced children rest inside a room they are currently living in, inside the rebel-held besieged eastern Ghouta of Damascus, Syria October 15, 2016. (Photo by Bassam Khabieh/Reuters)

Syrian women wait at the border gate to cross the Syrian town of Jarablus, in Karkamis, Turkey, October 19, 2016. (Photo by Umit Bektas/Reuters)

Members of Turkish-backed Free Syrian Army (FSA) patrol in the border town of Jarablus, Syria, October 19, 2016. (Photo by Umit Bektas/Reuters)

Members of Turkish-backed Free Syrian Army (FSA) are pictured the border town of Jarablus, Syria, October 19, 2016. (Photo by Umit Bektas/Reuters)

Members of Turkish-backed Free Syrian Army (FSA) stand in front of a wall where a portrait of Turkish President Tayyip Erdogan is displayed in the border town of Jarablus, Syria, October 19, 2016. (Photo by Umit Bektas/Reuters)

A man walks past damaged buildings in the rebel held besieged al-Sukkari neighbourhood of Aleppo, Syria October 19, 2016. (Photo by Abdalrhman Ismail/Reuters)

A man sits on the balcony of his damaged house in the rebel held besieged al-Sukkari neighbourhood of Aleppo, Syria October 19, 2016. (Photo by Abdalrhman Ismail/Reuters)

A man rides a bicycle near damaged buildings in the rebel held besieged al-Sukkari neighbourhood of Aleppo, Syria October 19, 2016. (Photo by Abdalrhman Ismail/Reuters)

Smoke rises from a building after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 19, 2016. (Photo by Bassam Khabieh/Reuters)

A Civil Defence member rubs his eyes as he tries to put out a fire inside a building after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 19, 2016. (Photo by Bassam Khabieh/Reuters)

Men walk amidst dust after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 20, 2016. (Photo by Bassam Khabieh/Reuters)

The hand of a dead child is pictured after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 20, 2016. (Photo by Bassam Khabieh/Reuters)

Men wrap a body with cloth after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 20, 2016. (Photo by Bassam Khabieh/Reuters)

Civil defense members search for survivors under the rubble of a site hit by overnight airstrikes in the town of Kafr Takharim, in Idlib Governorate, Syria October 24, 2016. (Photo by Ammar Abdullah/Reuters)

People inspect the damage at a site hit by overnight airstrikes in the town of Kafr Takharim, in Idlib Governorate, Syria October 24, 2016. (Photo by Ammar Abdullah/Reuters)

A man sits on the rubble of a damaged building at a site hit by overnight airstrikes in the town of Kafr Takharim, in Idlib Governorate, Syria October 24, 2016. (Photo by Ammar Abdullah/Reuters)

A man carries the body of dead child wrapped with cloth prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (Photo by Bassam Khabieh/Reuters)

A blood stained stretcher lies on a wall after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria October 24, 2016. (Photo by Bassam Khabieh/Reuters)

A man reacts over dead bodies prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (Photo by Bassam Khabieh/Reuters)

A boy inspects a damaged site after shelling in the rebel held town of Hass, south of Idlib province, Syria October 26, 2016. (Photo by Ammar Abdullah/Reuters)

Rebel fighters part of the Jabhat Fatah al Sham, attend military training in the besieged rebel held Aleppo, Syria October 26, 2016. (Photo by Abdalrhman Ismail/Reuters)

A rebel fighter part of the Jabhat Fatah al Sham, attends military training in the besieged rebel held Aleppo, Syria October 26, 2016. (Photo by Abdalrhman Ismail/Reuters)

Rebel fighters part of the Jabhat Fatah al Sham, attend military training in the besieged rebel held Aleppo, Syria October 26, 2016. (Photo by Abdalrhman Ismail/Reuters)

Boys inspect a hole in the ground after an airstrike near a playground on the besieged rebel held town of Douma, eastern Ghouta in Damascus, Syria, October 27, 2016. (Photo by Bassam Khabieh/Reuters)

Free Syrian Army members perform prayer before they attack Daesh positions at Tel Madik village of Mari district in Aleppo, Syria on October 25, 2016. The villages were cleared as part of Turkeys Operation Euphrates Shield. The anti-Daesh operation called “Euphrates Shield”, which was launched on August 24, aims at improving security, supporting coalition forces, supporting Syrias territorial integrity and eliminating the terror threat along Turkeys border through Free Syrian Army (FSA) fighters backed by Turkish armor, artillery, tanks and jets. (Photo by Huseyin Nasir/Anadolu Agency/Getty Images)

Syrian rebel fighters demonstrate fighting capabilities during a graduation ceremony in the northern Syrian city of Idlib on October 27, 2016. Syria's conflict erupted in March 2011 with protests calling for the ouster of President Bashar al-Assad. (Photo by Omar Haj Kadour/AFP Photo)

The body of a child is seen at a make-shift hospital following a cluster bomb attack on the rebel-held town of Douma, east of the Syrian capital Damascus, on October 24, 2016. (Photo by Abd Doumany/AFP Photo)

This frame grab from video provided by Muaz al-Shami, Syrian Revolution Network, an opposition activist media organization, that is consistent with independent AP reporting, shows two bodies lying down in the open back of a pick-up truck after airstrikes killed over 20 people, in the northern rebel-held village of Hass, Syria, Wednesday, October 26, 2016. A team of first responders, the Syrian Civil Defense in Idlib, said at least 50 were wounded in the raids that used parachute mines, targeting the residential area and schools in the village of Hass. Most of those killed were children, the group said on its Facebook page. (Photo by Muaz al-Shami/Syrian Revolution Network via AP Photo)

Maarouf, a 12-year-old Syrian boy waits to be rescued from the rubble of a building following a reported air strike on the the rebel-held Qaterji neighbourhood of the northern city of Aleppo on October 16, 2016. (Photo by Thaer Mohammed/AFP Photo)

A wounded Syrian child cries as he receives treatment at a make-shift hospital following reported government shelling on the rebel-held town of Douma, east of the Syrian capital Damascus, on October 26, 2016. (Photo by Abd Douman/AFP Photo)

Syrian children run for cover following reported government air strikes on the rebel-held town of Douma, east of the Syrian capital Damascus, on October 26, 2016. (Photo by Abd Douman/AFP Photo)

A wounded Syrian man receives treatment at a make-shift hospital following reported government shelling on the rebel-held town of Douma, east of the Syrian capital Damascus, on October 26, 2016. (Photo by Abd Douman/AFP Photo)